Butt splice connectors to extend INDOOR PV wire....Why not?

[energyhunter]

Appreciate any input. I'm upgrading to EG4 6000XP inverters and I need additional length for 8 connections of 10 AWG PV wire that is already indoors, to reach the new inverter connections.

Wouldn't tin plated copper butt splice connectors fit the bill for this use indoors? Seems like outdoor exposure arguments against wouldn't apply......even less when using marine grade multi wall adhesive lined heat shrink tubing with air/water tight seal....Rated to 600v.

This is what I'm looking at possibly using instead of MC4 connectors to slightly lengthen the indoor part of my PV wire:

Butt Splice Connector Pure Copper Tin-Coated Marine Grade Uninsulated

Create your cable connections with WindyNation's pure copper butt connectors. Perfect for RV's, boats, cars, trucks, cars, campers, ATV's, golf carts and a variety of applications where heavy duty battery cables, marine cables, or welding cables need to be spliced together! Insert spliced cables...

www.windynation.com

 

[seneysolar]

Appreciate any input. I'm upgrading to EG4 6000XP inverters and I need additional length for 8 connections of 10 AWG PV wire that is already indoors, to reach the new inverter connections.

Wouldn't tin plated copper butt splice connectors fit the bill for this use indoors? Seems like outdoor exposure arguments against wouldn't apply......even less when using marine grade multi wall adhesive lined heat shrink tubing with air/water tight seal....Rated to 600v.

This is what I'm looking at possibly using instead of MC4 connectors to slightly lengthen the indoor part of my PV wire:

Butt Splice Connector Pure Copper Tin-Coated Marine Grade Uninsulated

Create your cable connections with WindyNation's pure copper butt connectors. Perfect for RV's, boats, cars, trucks, cars, campers, ATV's, golf carts and a variety of applications where heavy duty battery cables, marine cables, or welding cables need to be spliced together! Insert spliced cables...

www.windynation.com

Go for it. Put connections in a junction box for future access if needed. Good crimp with good protection, no problem.

 

[energyhunter]

Go for it. Put connections in a junction box for future access if needed. Good crimp with good protection, no problem.

Thank you seneysolar, that's one!

 

[OffGridInTheCity]

My electrician used but-joints for my PV within a metal connection box and one of them arc'ed/failed in year 4 of operations!


I repaired it using lugs bolted together but there's 2 more that seem OK - you can see one wrapped in black electricians tape in pic below.
I can only assume the 'bad one' had a loose screw?!? but I don't really have any idea why it arc/burned thru after 4 years. A bit scary to tell the truth.


This was 6awg carrying up to 45a of combined PV about 100ft from the outdoor combiner boxes on the way to the charge controllers.

My advice would be to do it in a proper (metal?) connection box per code (I think it's code to have connection boxes where wires join)

I credit the metal box as protecting me from a fire under the floor of the house.

 

[energyhunter]

My electrician used but-joints for my PV within a metal connection box and one of them arc'ed/failed in year 4 of operations!
View attachment 203135View attachment 203138View attachment 203140

I repaired it using lugs bolted together
View attachment 203136View attachment 203139

This was 6awg carrying up to 45a of combined PV about 100ft from the outdoor combiner boxes on the way to the charge controllers.

My advice would be to do it in a metal connection box. I credit the metal box as protecting me from a fire under the floor of the house.

The box is a serious consideration. I should add that my butt connections link show a different connector then what you show here. Also mine would by crimped with Temco's hydraulic crimper for the best connection I could find prior to the marine grade adhesive heat shrink. Thank you for the warning OffGrid in The City.

 

[seneysolar]

My electrician used but-joints for my PV within a metal connection box and one of them arc'ed/failed in year 4 of operations!
View attachment 203135View attachment 203138View attachment 203140

I repaired it using lugs bolted together but there's 2 more that seem OK - you can see one wrapped in black electricians tape in pic below.
I can only assume the 'bad one' had a loose screw?!? but I don't really have any idea why it arc/burned thru after 4 years. A bit scary to tell the truth.
View attachment 203136View attachment 203139

This was 6awg carrying up to 45a of combined PV about 100ft from the outdoor combiner boxes on the way to the charge controllers.

My advice would be to do it in a proper (metal?) connection box per code (I think it's code to have connection boxes where wires join)

I credit the metal box as protecting me from a fire under the floor of the house.

Wow something went wrong here. Corrosion? Loose? Found a path to ground?
Splices done correctly should not pose a danger.

 

[Skypower]

I credit the metal box as protecting me from a fire under the floor of the house.

Your damn right it did!
I’m wondering if the electrician forgot to tighten or it loosened when arranging it into the box. Gives one pause if using plastic DIN breaker boxes for PV breakers.

 

[energyhunter]

Your damn right it did!
I’m wondering if the electrician forgot to tighten or it loosened when arranging it into the box. Gives one pause if using plastic DIN breaker boxes for PV breakers.

Good point Skypower

 

[Checkthisout]

Can't you just use wire nuts in a junction box?

 

[wheelman55]

OP. I use these Polaris Grey connectors inside a metal junction box. These are pro quality.

https://nsi-sales.com/pdf/Polaris.pdf

 

[Mattb4]

Why not MC4 connectors?

 

[seneysolar]

Why not MC4 connectors?

Im not sure a pair of mc4 connectors would fit in a box? Just thinking code compliant, having a connection inside.

 

[Sennen]

I like the idea of the crimped and shrunk butt. But indeed in a jb

 

[energyhunter]

Can't you just use wire nuts in a junction box?

I'm just a novice but it seems hard to trust an unsealed wire nut with 600v.

 

[energyhunter]

OP. I use these Polaris Grey connectors inside a metal junction box. These are pro quality.

https://nsi-sales.com/pdf/Polaris.pdf

The Polaris connectors seem bulky and approaching the older example that seneysolar shared which aren't the slim style pictured in my windynation link that lend themselves to marine type 4:1 heat shrink with adhesion that Will P liked at this link:

Durable Heat Shrink for PV Butt Splice Connections

Typically I do not get excited over heat shrink, but today I think I found my favorite. It is lined with adhesive and when it cools down, creates an incredibly strong connection between two PV wires. This is for those of you who prefer butt splicing their PV cables instead of using MC4 for PV...

diysolarforum.com

 

[energyhunter]

I like the idea of the crimped and shrunk butt. But indeed in a jb

I should clarify that my reasoning to begin with was to do away with the isolator disconnect since the 6000XP has it internally, but if you need a junction box anyway it kind of defeats the purpose. Even though there is disconnect duplication, maybe I should just leave the isolator switches in place for the safety of extending the lower PV wires while the switch is off.

 

[energyhunter]

I like the idea of the crimped and shrunk butt. But indeed in a jb

Thanks Sennen

 

[energyhunter]

Why not MC4 connectors?

I was trying to avoid the bulky ness and more- outdoor-related-need for the MC4s.

 

[Quattrohead]

I'm just a novice but it seems hard to trust an unsealed wire nut with 600v.

Wire nuts are rated to 600 volts and actually make a great connection. I was very pessimistic when I first came to the USA but now I appreciate them for what they are and how they work.
But yes DC wiring should always be in a metal conduit and box, as the other poster showed here it saved his bacon.

 

[Quattrohead]

Why not MC4 connectors?

Many people don't have the equipment to install mc4 connectors